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Replacing 24-year-old Noisy Furnace--Looking for Advice

Hi,

We are replacing a 24-year-old furnace in a condominium that has a faulty valve. It will cost around $$$ to replace the valve and that seems unwise in a furnace this old. It is an upflow configured furnace (Train BLUI62F960B2 with a Bryant coil). It is in a mechanical closet with a water heater, and a ductless return which is facing the main living space. It is very noisy, and we are told the system is oversized. Our primary concern is noise and cost; we are trying to sell the unit but could be here awhile in this market.

I am told that an 80% efficiency unit makes the most sense due to venting issues. We are on the 2nd and 3rd floor of a three story building, new venting required for higher efficiency units seems impractical. Our square footage is around 2000, and we have some additional air volume with sloped cathedral ceilings.

One estimate I received was for a Coleman modulating 80 furnace with new coil and condenser. I liked this bid, but my concerns are two fold: the contractor specified an identical 5-ton size, while other contractors told us we didn't need such a large unit. Second, if sized correctly, I'm concerned that it will run constantly. This would make the noise factor critical. (It's one thing for a manufacturer to claim it is quiet and another for it to truly be quiet.)

A second option I am considering, but haven't priced, is a Rheem combination tankless heater and furnace. This would replace the equally old water heater, and by removing the water heater from this closet might allow us to place the return in a hallway at right angle to the living space. This would involve some duct work/drywall removal.

1) How do I find out the correct size--is a manual J calc necessary, or can i trust someone's judgment?

2) Do you think it is worth the extra cost to relocate the return (i.e. go with a tankless Rheem system) or should I just go with a modulating furnace, such as the Coleman? (The Rheem would be a two stage, I believe.)

3) Is there a way to find out the actual dBs of the blowers?

Any input would be greatly appreciated, as well as any other suggestions, or alternative equipment to consider.

Must be one huge condo to need that monster furnace and 5 ton drive. 1st step is accurate load calc. Odds are it doesn't need that big unit. Moving less air will quiet things down. Ducted return will help or have them build a box under it and insulate it. A picture of the install would help us understand how it is down now. Ductless return and a water heater in the same closet sounds dangerous now that I think of it.

Must be one huge condo to need that monster furnace and 5 ton drive. 1st step is accurate load calc. Odds are it doesn't need that big unit. Moving less air will quiet things down. Ducted return will help or have them build a box under it and insulate it. A picture of the install would help us understand how it is down now. Ductless return and a water heater in the same closet sounds dangerous now that I think of it.

I don't know why it is upside down, but that's the furnace, return register and water heater visible in background (white). I tried posting a flipped version of it and it is still upside down.

What size is the A/C. You said 5 ton, but I think you might have been talking about the blower.

I agree with B.L. The new furnaces are much shorter which will allow for a box under.

If there is room, on the side or under the furnace, for a hi-efficiency filter, they do a great job of quieting the noise.

A commercial grade, properly sized RA grille would also help.

The blower is definitely 5 tons. The furnace model number is above, I can't find anything on it due to the age. It is rated to 162,000 BTU/hr, if that tells you anything about the size (I believe it is five tons). It is definitely oversized, no question about that. On for awhile then off for an equal period. The question is, what size should it be? I talked to one contractor about a manual J calc, but there is a significant cost involved. Are there other estimating methods?

So, putting it on a box would mean creating a right angle in the return air, if my understanding of what you are suggesting correct. The headroom in the closet is 7 feet, floor to ceiling.

Would a larger grill make a difference, we might be able to increase the width somewhat (~6") and the height--or are we better matching the grill size to the return size of the unit? Thanks.

the cost of not doing a man j will be far greater (any contractor that doesnt do man. j is just guessing) so what else are they going to guess on quality ,safety, ect. ect.!!!!do your homework get sevral bids and refrences you may even ask to see some recent installs of theirs